<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_外间距测试</title>
    <style>
        div {
            margin: 0;
            padding: 0;
        }
        .fu {
            background-color: rgba(255,255,0,.3);
            overflow: hidden;
        }
        .fu>div {
            width: 100px;
            height: 100px;
            background-color: rgba(0,0,255,.6);
            border: 2px solid blue;
            color: #fff;
            font-size: 25px;
            font-weight: bold;
        }
        .z1 {
            margin-bottom: 20px;
            margin-top: 20px;
        }
        .z2 {
            margin-top: 30px;
        }
        .z3 {
            margin: 10px 20px 10px 0px;
        }
        .z4 {
            margin: 10px 20px 30px;
            margin: 0 auto;
        }
        span {
            border: 2px solid red;
        }
        .s2 {
            margin: 10px;
        }

    </style>
</head>
<body>
<span>span1</span><span class="s2">span2</span><span>span3</span>
<div class="fu">
    <div class="z1">1</div>
    <div class="z2">2</div>
    <div class="z3">3</div>
    <div class="z4">44</div>
</div>
</body>
</html>